1. Field of the Invention
The present invention relate in general to torque transmitting devices, and more particularly to torsional vibration dampers of the kind suited for use with internal combustion engines.
2. Description of the Related Art
An example of this kind of torsional vibration damper assembly in disclosed in U.S. Pat. No. 4,530,673. The vibration damper assembly includes a housing serving as an input element and having drive straps, a hub on which the housing is journaled, the hub having two circumferentially spaced radial hub arms, a compression spring received within the housing and extending between the edges of adjacent hub arms and drive straps, and wedge-shaped dividers inserted between adjacent coils of the spring.
The dividers are provided for dividing the spring into several functioning spring segments, whereby to provide the vibration damper assembly with high deflection amplitude characteristics.
The dividers are adapted to be guided by the housing by being brought into contact at outer arcuated support surfaces thereof with the inside surface of the housing.
In operation, the dividers are urged against the housing by the centrifugal force of itself and the centrifugal force of the compression springs. Thus, when the dividers are caused to slide within the housing while being guided by same, there is a possibility that a large hysteresis in the torsional vibration damping action is caused, thus disabling to provide stable torsional vibration damping characteristics.
An object of the present invention is to provide a torsional vibration damper assembly which is free from the above described hysteresis in the torsional action or torsional vibration damping action and has stable torsional vibration damping characteristics.
To achieve the above object, there is provided according to an aspect of the present invention a torsional vibration damper assembly comprising a pair of first and second torque transmitting elements rotatable relative to each other, a damper hub operatively connected to the first torque transmitting element and having a plurality of circumferentially spaced radial hub arms, a plurality of compression springs disposed between the second torque transmitting element and the hubs arms, and a ring member surrounding the compression springs and having an inner circumferential side capable of contacting radially outer peripheries of the compression springs.
According to another aspect of the present invention, there is provided a torsional vibration damper assembly comprising a pair of first and second torque transmitting elements rotatable relative to each other, a damper hub operatively connected to the first torque transmitting element and having a plurality of circumferentially equally spaced radial hub arms, a drive plate operatively connected to the second torque transmitting element and having a plurality of circumferentially equally spaced windows, a plurality of compression springs extending between circumferentially opposed edges of the windows and the hub arms, and a ring member rotatable relative to the first and second torque transmitting elements and surrounding the compression springs for restricting radially outward bending of the compression springs.